Triterpenoids and their saponins from Ilex Asprella: Types and biological studies

The plant Ilex asprella (Hook. et Arn.) Champ. ex Benth. (Aquifoliaceae) is a deciduous shrub growing in southern China and Southeast Asia. The roots of I. asprella, known as Gangmei in China, have been widely used as a Traditional Chinese Medicine (TCM) for the treatment of headaches, coughs, fever, diarrhea and sore throats. In addition, its root is key ingredient of ‘Wang-Lao-Ji Herbal Tea’ which was formulated in 1828 and has been widely accepted as a healthy beverage. Previous investigations on the phytochemistry of this plant had led to the isolation of triterpenoids, flavonoids, phenolic acid and alkaloid phenolic compounds. The most characteristic constituents of I. asprella are triterpenoids and their saponins, including some rare sulfur-containing derivatives. Pharmacological research has identified the important associations of I. asprella with their anti-cancer, anti-inflammatory, and anti-virus activities. This chapter will focus on the structural types and biological studies of saponins of I. asprella, and the characteristics of these chemical structures will also be briefly discussed.